Draft control for heating



July 29,1952 A. H. zlPH DRAFT CONTROL FOR HEATING APPARATUS Filed March 2T. 195o Sheets-Sheet 1 ,/n. r. w.

W fl July 29, 1952 A. H. zlPH DRAFT CONTROL FOR HEATING APPARATUS 3 Sheets-Shea?l 2 Filed March 27, 1950 INvzNroR, /drew H'. Z

July 29, 1952 A. H. zlPH I 2,604,887

DRAFT CONTROLV RoR HEATING APPARATUS Filed March 27, 195o 3 sheets-sheet s Patented July 29, 1952 OFFICE DRAFT CONTROL FOR AHEATING APPARATUS yAndrew H. AZiph, St. Joseph, Mo. Application-Maren 27, 1950, serial No. 152.089 i1 claims. (oi. 12s-307.)

This invention relates to `improvements infdraft control for heating apparatus, vand has particular reference to the control and rregulation offthe up Aand down drafts especially in domestic heating installations.

The principal object of this invention is the provision of la back draf-.t Ydiverter that automatically diffuses and Vmakes ineffective excessive 'back or-down drafts that-are often severeenough to :snuff out the pilot or low-lire flame, especially infoil or gas-fired installations.

An inherent weakness lof the 'back draft diverter now on the market `is that the annular open space Aat the bottom of the hood, called the -re'liefr opening, communicates directly with-the `inside of the pipe. 'The reason that this constitutes .a weakness lies the ifact that draft conditions vary withatmospheric pressure, temperature, wind velocity, height and location of the chimney, `intermittent operationof the appliance, vand many'otherchanging conditions. Therefore, since .in laback draft diverter the pipe has direct communication with the variableconditions existent at the outside ofthe pipe, all these variations will'be communicated undinfiin'ished tothe inside of the pipe 'withtheconsequent lowered combustion-eflicency that results from an Iextremeirange of draft conditions. 'f

'To correct and minimize `.these effects, itfis common practice to make `use `of 'draft regulators (also called barometric dra-ft controls) r which :check excessive up 'drafts (as opposed to down drafts mentioned with respect to down draft ,-hoods), and equalizes chimney draft so that it is possible 'to :assure a comparatively constant draft Wherever an 'installation is subjected to more than normal draft pressure. y

An :inherent weakness of a draft Acontrol such as described above is the fact that Yit-ca-Imyotfunction whenever draftfconditions are less than lthe value forwhich the.regulatorisadjusted Therefore Yit 'is impossible, and has neverfbeen :a recommended practice, to use a draftfr'egulator in conjunction withta lback draft diverter (although a highly desirable combination) `because the one in accomplishing its useful function directlyopposes the other and 'vice versa.

Some attempts have been made to overcome these diiculties by internal damper Aarrange- Jmentsybut have not Vbeen :very successful because of the corrosive effects of the products of combustion on the vdamper and pivot Vpins when in direct `contact therewith, and for other inherent vdifficulties rin design.

YTheprincipal object of the'present invention is,

therefore, to y:provide a combination of a back draft diverter and draft regulator `that will perform both functions without interference therebetween, thus allowing the single lunit to accomplish both -back draft Aand u-p draft control'ef- `fectively.

Another object is to provide a back draftdiverter only with means to control back draftsand va-t-the 4same time to overcome its inherent Weaknesses by closing the relief opening that directly connects the outside and inside ofthe device, with provision to open it lonly as necessity arises ,due to back or down drafts occuring in the chimney andsmoke pipe.

AA further object is Vto provide a back draft diverter with two semi-circular annular plates or aps that vpivot on va line through the major diameter of the plates so that said plates 'can swing angularly yfrom their normally closed Vposition to an-open position thus allowingthe diffusion of back drafts with no ill effects on the operation of the heating appliance. y

Still another object is to provide theflapswi'th va system -of weights and means for adjustin'gsaid weights so lthat equilibrium of the flaps caribe adjusted to holdthem in perfect balance ortoun- .balancethe flaps eitherpositively ornegatively according to the operating,requirementsof the device.

Another object is to provide-a system of sensitivepivotpoints Vfor the swingable flaps at points outside the path-of the kgaseous products of combustion lso that no `undue corrosion or pitting will occur Yto-disturb the sensitive balance of the flaps.

Other objects -are simplicityand economy both in the oper-ation and production of the device,

the provisi-on of parts that can be speedily produced on automatic machines, and the provision of a devicethat can vbe installed in any heating vsmoke pipe line easily vand 'simply by inserti-ng standard sectionsof pipe in both inlet and outlet connections in the same manner as is JAcustomaryin present practice with respect to heating installations.

With theseobjects in View, Vaes-'well as other objects vwhich will appear in the course of .the specification, reference will be had to the drawing, wherein:

Figi is asideelevation of a draftcontrolai paratus Afor controlling ith-e various Vdrafts of com- `bustion equipment, embodying the present invention Fig. 2 is'anelevaticnal View .ofthe draft-.G011- trol Vapparatus shown at right Yangles tot-hat shown in Fig. 1, with the upper portion thereof shown in section to show the open position of the draft flaps.

Fig. 3 is an enlarged horizontal sectional View taken on line III- III of Fig. 1, showing the flap mechanism in plan.

Fig. 4 is an enlarged fragmentary sectional View taken on line IV-IV of Fig. 3.

Fig. 5 is an enlarged elevational view of the balancing for the draft flaps.

Fig. 6 is an elevational view of a draft control means applied to a modified L -shaped back draft delector with draft control means shown in dotted lines.

Fig. '7 is an elevational view of a vertical type standard back draft diverter shown provided with the present draft control means.

Fig. 8 shows the application of the improved draft control means as applied to the horizontal type of back draft diverters, a side of which is partly broken away to disclose the draft control means in the closed position in solid lines and in dotted lines in the open position.

Fig. 9 is a perspective view of one of a series of brackets that serve to join separate parts of the back draft diverted together by spot welding.

Like reference characters refer to similar parts throughout the several views, and the numeral 2 designates a stovepipe T-joint in which is installed a draft regulator of common type, said regulator comprising essentially a damper door 40a hung on a horizontal pivot 4Gb above its center of gravity and counterbalanced by weights 40e adjustable on a screw 40d fixed in said door. The body of said T-joint projects upwardly into the draft hood I in spaced relation below draft cone 42. The said T-joint, draft hood and draft cone 42 are joined together by means of three like brackets 43, 44, and 45 equally spaced apart about said stovepipe T-joint and jointed to the various parts by welding. At points diametrically opposed on both the outer periphery of the draft hood and the circumference of the stovepipe T-joint, pins t1 have their bearings.

The inner ends of pins I1 are headed and the outer ends are flattened, 38 and 39, at the time of assembly to secure them in place so they will not move endwise out of their bearing positions.

Pins I1 support tabs 35, 34, 33, and 32, Fig. r

4, which are upturned from semi-circular aps 36 and 31, forming pivotal bearings for the flaps which swing on pins I1 at the several bearing points provided by the upturned tabs. Spacer bushings 23, v21, 26, 25, and 24 position flaps 36 and 31 between the bearing points of pins I1 in the upper end of stovepipe T-joint 2 and the lower end of hood I.

The upper end of T-joint 2 is secured to three equally spaced brackets, all of which 43, 44, and 45 are shown, by spot welding to Youtwardly turned tabs 53, Fig. 9, In turn outwardly turned tabs 52 of said brackets are spot welded to draft 4hood and tabs 5|, are spot welded to double cone 42. The assembly of these parts forms the devices shown in Figs. 1, 2, 6, and '1. The draft deecting cone 42 consists of a single cone cupped upwardly in ordinarily used back draft diverters, but for the purposes of this invention the cone is double, with the long apex at the top to provide a draft deflecting surface which directs the pressure or weight of the down draft against the surface of flaps 36 and 31, while the short apex of cone 42 directs the upwardly flowing gas around the deflecting cone and thence to the outlet passage 41.

Flaps 36 and 31 are semi-circular in shape on their outside peripheries but their inner peripheries are given an elliptical curvature in order to provide clearance spaces 36 and 3l about the circumference of the T-joint at their pivot points. This clearance space is provided so that when the aps rotate to an angular position such as shown in Fig. 2, the inner peripheries of the flaps will not strike the circumference of the T-joint until sufficient opening has been attained to allow back drafts to diffuse and escape to the outside atmosphere.

Rods 8 and 22 are threaded or secured in brackets 3 and I2 at their ends, and brackets 3. I2, I6, and I8 are secured to flaps 36 and 31 to hold them in angular position on the aps or plates so that the ends of rods 8 and 22 whenformed approximately semi-circular in shape will coincide with the threaded openings of the bracketsin which they are secured.

Along the axis of the rods 8 and 22 are formed rolled threads represented by I5 and 20 which can be rolled the full length of the rods or in the sections only where the weights I9, 2|, 23, and I4 are carried, to provide means for positioning said weights so that the center of gravity of the flaps 36 and 31 can be shifted relative to the pivot points to bring said flaps into perfect equilibrium in a horizontal plane, or to shift the center of gravity to any desired points.

Normally a sensitive balance of the flaps in a horizontal plane is desired so that the slightest weight due to draft pressure thereon will cause them to swing angularly downwardly. When the pressure on the upper surfaces is relieved or dissipated through the resulting opening between draft hood I and the end of the T-joint 2 which projects upwardly inside the hood, the equilibrium of the flap will again cause them to assume their horizontal plane position, thus closing the opening communicating between the outside and inside of the draft hood. When the flaps are open due to back draft, draft regulator 40 becomes inoperative and remains in its closed position. After the back draft has been diffused and updraft reestablished, the flaps close the relief opening of the back draft hood automatically and draft regulator 40 again becomes operative to automatically check excessive draft, thereby maintaining a constant pre-set overre draft in the heating appliance.

Brackets 43, 44, and 45 are provided with a cut-out space 6| at their lower ends to provide clearance for the adjustment rods and weights to swing upward as shown in Fig. 2 when flaps 36 and 31 are forced downwardly by back pressure on their upper surfaces.

Openings 46 are provided to ccnnectthe inlet endsof the devices described herein to a pipe which is directly connected to the iiue of the heatingappliance, while opening 41 connects to the remainder of the smoke pipe run which leads to the chimney or stack.

In the modification shown in Fig. 6, the device is shown in elbow or L-form, pipe 54, hood 55, and pipe 56 thereof corresponding with pipe 2, hood I, and outlet 41 of Fig. 1. except that pipe 56 is disposed at right angles to the axis of the hood.

Exactly the same pivot suspension arrangement is-carried out in the flaps of thisdevice except that one pivot pin `I1 extending clear through the rectangular opening is 'used instead of two 'as' in the preceding cases and thefspacer bushings are .made suitable' to hold'the rectangulariiap's in correct alignment and position.

The adjustment rods, weights and fittings are exactly similar in shape to those described for the preceding devices but vthe size of the kweights are varied to suitv thev individual requirements of any given size of diverter which embodies the flaps.

The above reference to size of parts is also true in allcases described before, that this Lin'- ventionV is intended fora complete range .ofgsizes to suit every heating installation by varying-'the size ofv parts to ccnformto therequiredasizefof the device. y

Thus it is apparent from the preceding description and specicatonthat a combination back draft diverter and draft 'regulator has been produced which may function both as a back draft diverter and draft regulator in the only manner in which the combination. can be successfully made; that is,.by`means of the flaps which open or close, automatically by meansiof draft pressure changes actuating: the V component v elements of the device. f

Similarly it is also apparent that a back-draft diverter has been produced that will `perform its functions of back draft relief while retaining the elements of safety, efficiency and economy afforded by providing a relief opening. that is opened or closed automatically vin accordance with variations in draft conditions caused by outsideV influences beyond control, such as atmospherc pressure, temperature, wind velocity, height and location of chimney, intermittent operation of the appliance, andother variablafac.- tors. ...-,f '3

' Both with and without the-'combination gof draft regulation, the back draft diverter-thus provides4 a new and improved combination and useful improvement that creates .greater,safety,

better efficiency, and maximum economy inathe operation of fuel red combustion equipment Vof any type, but especially with respectto oil and gas fired equipment.

What I claim as newand desire-to protect by Letters Patent is: 0 1. A back draft deflector assembly comprising a frusto-conical shaped hood, a combustion gas receiving stove-pipe propecting axially into the lower portion ofsaid hood in spaced relation to the outer periphery of .saidA hood, to present an annular space therebetween, a double cone shaped draft' deflecting baiiie disposed in axial alignment in said hood in spaced relation above said stove-pipe,spa'ced` apart bra'clets' for "securing said hood, stove-pipe, and baffle in relatively fixed relation, means adapted to connect the upper end of said hood witha draft flue, a

`pair of hingedly mounted flat plates to provide means to automatically close said annularspaee about said stove-pipe, each of said plates being provided with counter-balancing means whereby said plates will normally close said annular space, and whereby down drafts through said draft flues will exert a pressure on said plates to pivot said plates to open said annular space.

2. A back draft diverter assembly comprising a substantially frusto-conical shaped hood provided at its base with a cylindrical inlet pipe of lesser diameter adapted to connect the inlet of said hood with the discharge flue of a fuel burning appliance, a double cone shaped draft deflecting baffle supported above the cylindrical inlet to provide a substantially annular passage in conformance withthehood a pair 'of substantially semi-circularxflat:plate segmentsv vhinged diametrically to provide a means forA automatically closing the annular space formed by the baseof said conically shaped hood with said' cylindrical inlet pipe, said segments being provided with adjustable counter-balancing means to balance said segments individually. I

3,. A back draft .deflector assembly .comprising a frustoeconical shaped hood adapted to be connected at its'upper end with a draft flue, a stove pipe provided with a draft regulator and adapted to communicate with a combustion chamber to deliver heated gases into the body of said hood, a substantially cone shaped ldeiiector lmounted in said hood in -xed relation thereto rand in spaced relation above said stove pipe, wherebya substantially annular space is provided between said hoodand stove pipe, and a pair of substantially semi-circular flaps hinged to automatically operateto control the down draft throughsaid annular space vwhereby the major portion -ofr said down, draft will be dissipated to-.the atmosphere. 4. A back draft deector assemblycomprising a frustofconical shaped hood, a T-jointstove pipe section having an automatic draft regulator damper therein adapted to communicate at its lower end with a combustion chamber and open at its upper ,end to conduct gases axially intov the lower portion of said hood, a cone shaped draft deiiectingbaiiie disposed in axial alignment above the upper end portion of said stove pipe, means for securing said hood, stove pipe, and baffle in fixed' relation to present a fixed annular space between said hood and stove pipe, a pair of substantially semi-circular ring plates vindependently mounted to normally close said annular space, and 4having l counterbalancing means whereby back drafts delivereil-tov said hood will open said annular space to direct the backv drafts therethrough to the atmosphere. v

5. A back draft deflector and draft regulator assembly for fuelburning appliances comprising a frusto-'conical hood, a stove pipel provided with an updraft regulator damper therein adapted to communicate at its lower yend with'a combustion chamberand'ope'n at its upper end'to conduct gases axially into the'lower portion of said'v hood, a cone shaped draft deflecting'bafle disposed in axial alignment above the upper end portion of saidstoven pipe, means for securing saidghood, 'stove'pipe, and baffle in fixed relation to present aiixedlannular space between Vsaid hood and stovefpipe, va pair of substantially semi-circular ringl plates independentlyY mounted to normally close said annular space, and'having counterbalancing means whereby back drafts delivered to said hood will open said annular space to direct the back drafts therethrough to the atmosphere.

65A back draft regulator adapted to `be inserted in a flue leading from'a heatingchambe'r to a chimney comprising a frusto-conical shaped hood, a stove pipe adapted to communicate at its lower end with a combustion chamber and open at its upper end to conduct gases axially into the lower portion of said hood, a cone shaped draft deecting baffle disposed in axial alignment above the upper end portion of said stove pipe, means for securing said hood, stove pipe, andbaiile in fixed relation to present a fixed annular space between said hood and stove pipe, a pair of substantially semi-circular ring plates independently mounted to normally close said annular space, and having counter-balancing means whereby back drafts delivered to said hood will` open said annular space to direct the back drafts therethrough to the atmosphere.

7. A back draft deiiector assembly comprising a frusta-conical shaped hood, a T-.joint stovepipc section having an automatic draft regulator intermediate its ends adapted to communicate at its lower end with 'a combustion chamber and open at its upper end to conduct gases axially into the lower portion of said hood, a cone shaped draft deiiecting baiile disposed in axial alignment above the upper end portion of said stove pipe, means for securing said hood, stove pipe T-joint, and baffle in fixed relation to present a fixed annular space between said hood and stov'epip'e, a pair of substantially semi-'circular V`ring plates independently mounted to normally close said annular space, and having counter-balancing means whereby back drafts delivered to said hood will open said annular space to direct the back drafts therethrough to the atmosphere, whereupon said semi-circular ring plates will return to the closed position as the up draft is reestab lished, thus enabling the draft regulator to check excessive up drafts andto maintain a constant, uniform draft in the combustion chamber of the heating appliance. Y 8. A back draft deiiector assembly comprising a frusto-conical hood open at its lower end and adapted to communicate at its upper end with a flue, a stove-pipe adapted to communicate at one end with a combustion chamber and having its open opposite end extending axially upwardly into the lower portion of said hood, a coneshaped draft deflecting baflie disposed axially in said hood in spaced relation above the end of said pipe, means for securing said hood, stove-pipe, and baffle in fixed relation to present an annular space between said hood-and stove-pipe, a pair of substantially semi-circular ring plates carried pivotally by said assembly and adapted to close said annular space, said ring plates being adapted to be opened outwardly by back draft pressure Within said hood, and counter-balancing weights whereby said ring plates are yieldably urged toward their closed position.

9. A combination draft regulator and back draft deflector comprising a frusto-'conical hood open at its lower end andadapted to communicate at its upper end with a flue, `a stove-pipe adapted to communicate at one end with a combustion chamber vand having its open upper end extending axially upwardly into the lower portion of said hood, said stove-pipe having an opening therein outside of said hood and communieating with the atmosphere, a draft regulating damper controlling said opening, a cone-shaped draft defiecting bailler disposed axially in said hood in spaced relation from the end of said pipe, means for securing said hood, stove-pipe, and baffle in xed relation to present an annular space between said hood and stove-pipe, a pair of substantially semi-circular ring plates carried pivotally by said assembly and adapted to close said annular space, said ring plates being adapted to be opened outwardly by back draft pressure within said hood, and counter-balancing Weights whereby said ring plates are yieldably urged toward their closed position.

10. A back draft defiector assembly comprising a frusto-conical hood open at its lower end and adapted to communicate at its upper end with a due, a stove-pipe adapted to communicate at one end with a combustion chamber and having its open -opposite end extending axially upwardly into the lower portion of said hood, a double cone-'shaped draft deiiecting baiiie disposed axially in said hood in spaced relation above the end of said pipe, means for securing said hood, stove-pipe, and baie in fixed relation to present an annular space between said hood and stovepipe, a pair of substantially semi-circular ring plates carried pivotally by said assembly and adapted to close said annular space, said ring plates being adapted to be opened outwardly by back draft pressure within said hood, and counter-balancing weights whereby said ring plates are yieldably urged vtoward their closed position.

11. A back draft deiiector assembly comprising a frusto-conical hood open at its lower end and adapted to communicate at its upper end with a flue', a stove-pipe adapted to communicate at one end with a combustion chamber and having its open opposite end extending axially upwardly into the lower portion of said hood, a cone-shaped draftY deflecting baiil'e disposed axially in said hood in spaced relation above the end of said pipe, means for securing said hood, stove-pipe, and baiiie in fixed relation to present an annular space between said hood and stove-pipe, a pair of substantially semiecircular ring plates carried pivotally by said assembly and adapted to close said annular space, said ring plates being adapted to be opened outwardly by back draft pressure within said hood, and counter-balancing weights whereby said ring plates are yieldably urged toward their closed position, said weights being adjustable whereby they vary the back draft pressure required to open said ring plates.

ANDREW H. ZIPH.

REFERENCES orrnn The following references are 'of record in the ille'of this patent:

UNITED STATES PATENTS vmana; ,Y Name Date V1,760,007 Schaller May 27, 1930 1,891,600 Lancaster Dec.v 20, 1932 '1,928,822 ySchmidt Oct. 3, 1933 2,030,825 'Pembroke Feb. 11, 1936 2,127,100 Whitaker Aug. 16, 1938 2,344,947 Martin f Mar. 28, 1944 

